<script>
import $ from 'jquery';
import DiffTableCell from './diff_table_cell.vue';
import {
  NEW_LINE_TYPE,
  OLD_LINE_TYPE,
  CONTEXT_LINE_TYPE,
  CONTEXT_LINE_CLASS_NAME,
  OLD_NO_NEW_LINE_TYPE,
  PARALLEL_DIFF_VIEW_TYPE,
  NEW_NO_NEW_LINE_TYPE,
  EMPTY_CELL_TYPE,
} from '../constants';

export default {
  components: {
    DiffTableCell,
  },
  props: {
    fileHash: {
      type: String,
      required: true,
    },
    contextLinesPath: {
      type: String,
      required: true,
    },
    line: {
      type: Object,
      required: true,
    },
    isBottom: {
      type: Boolean,
      required: false,
      default: false,
    },
  },
  data() {
    return {
      isLeftHover: false,
      isRightHover: false,
    };
  },
  computed: {
    isContextLine() {
      return this.line.left && this.line.left.type === CONTEXT_LINE_TYPE;
    },
    classNameMap() {
      return {
        [CONTEXT_LINE_CLASS_NAME]: this.isContextLine,
        [PARALLEL_DIFF_VIEW_TYPE]: true,
      };
    },
    parallelViewLeftLineType() {
      if (this.line.right && this.line.right.type === NEW_NO_NEW_LINE_TYPE) {
        return OLD_NO_NEW_LINE_TYPE;
      }

      return this.line.left ? this.line.left.type : EMPTY_CELL_TYPE;
    },
  },
  created() {
    this.newLineType = NEW_LINE_TYPE;
    this.oldLineType = OLD_LINE_TYPE;
    this.parallelDiffViewType = PARALLEL_DIFF_VIEW_TYPE;
  },
  methods: {
    handleMouseMove(e) {
      const isHover = e.type === 'mouseover';
      const hoveringCell = e.target.closest('td');
      const allCellsInHoveringRow = Array.from(e.currentTarget.children);
      const hoverIndex = allCellsInHoveringRow.indexOf(hoveringCell);

      if (hoverIndex >= 2) {
        this.isRightHover = isHover;
      } else {
        this.isLeftHover = isHover;
      }
    },
    // Prevent text selecting on both sides of parallel diff view
    // Backport of the same code from legacy diff notes.
    handleParallelLineMouseDown(e) {
      const line = $(e.currentTarget);
      const table = line.closest('table');

      table.removeClass('left-side-selected right-side-selected');
      const [lineClass] = ['left-side', 'right-side'].filter(name => line.hasClass(name));

      if (lineClass) {
        table.addClass(`${lineClass}-selected`);
      }
    },
  },
};
</script>

<template>
  <tr
    :class="classNameMap"
    class="line_holder"
    @mouseover="handleMouseMove"
    @mouseout="handleMouseMove"
  >
    <template v-if="line.left">
      <diff-table-cell
        :file-hash="fileHash"
        :context-lines-path="contextLinesPath"
        :line="line.left"
        :line-type="oldLineType"
        :is-bottom="isBottom"
        :is-hover="isLeftHover"
        :show-comment-button="true"
        :diff-view-type="parallelDiffViewType"
        line-position="left"
        class="diff-line-num old_line"
      />
      <td
        :id="line.left.lineCode"
        :class="parallelViewLeftLineType"
        class="line_content parallel left-side"
        @mousedown.native="handleParallelLineMouseDown"
        v-html="line.left.richText"
      >
      </td>
    </template>
    <template v-else>
      <td class="diff-line-num old_line empty-cell"></td>
      <td class="line_content parallel left-side empty-cell"></td>
    </template>
    <template v-if="line.right">
      <diff-table-cell
        :file-hash="fileHash"
        :context-lines-path="contextLinesPath"
        :line="line.right"
        :line-type="newLineType"
        :is-bottom="isBottom"
        :is-hover="isRightHover"
        :show-comment-button="true"
        :diff-view-type="parallelDiffViewType"
        line-position="right"
        class="diff-line-num new_line"
      />
      <td
        :id="line.right.lineCode"
        :class="line.right.type"
        class="line_content parallel right-side"
        @mousedown.native="handleParallelLineMouseDown"
        v-html="line.right.richText"
      >
      </td>
    </template>
    <template v-else>
      <td class="diff-line-num old_line empty-cell"></td>
      <td class="line_content parallel right-side empty-cell"></td>
    </template>
  </tr>
</template>
